This invention relates to hydraulic systems for providing automatic proportioned actuation of pairs of hydraulic cylinders. Prior art devices generally use mechanical linkages for effecting proportional control. These mechanical linkages are often bulky and add considerable complexity to the system. Necessary clearances in the mating parts results in a substantial amount of play within the linkage system. This can be minimized by holding very close tolerances, however, this will greatly increase the cost of the mechanism.
Other prior art proportioning devices utilize all hydraulic components. Such devices use complex valving arrangements which are costly to manufacture and to maintain. These devices usually contain spool valves and restrictor valves containing delicate plungers, springs, accurately spaced ports and, in general, very closely fitting parts. This generally necessitates complex hydraulic interconnections.
What is needed is an automatic proportioned actuating hydraulic circuit composed exclusively of hydraulic components without the complex valving arrangement described above.
It is therefore an object of this invention to provide a proportioned hydraulic system of simple construction that is economical to manufacture.
It is another object of this invention to provide a proportioned hydraulic system utilizing all hydraulic components for effection proportioned control.
It is another object of this invention to provide a proportioned hydraulic system wherein proportioned control is effected by standard, commercially available hydraulic cylinders.